119 terms

# Statistics Exam 1

Salkind, Chapters 1 - 6
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What term is used to describe the science of organizing and analyzing information to make the information easily understood?
Statistics
Which of the following individuals used statistics methods during the 17th century to study the intelligence of his family members?
Francis Galton
Which of the following would be used to describe the type of statistical methods used to organize and describe the characteristics of a collection of data?
Descriptive statistics
Which of the following would be used to describe the type of statistical methods used to make inferences about the population based on a sample?
Inferential statistics
What is a mathematical operator used to perform a mathematical task called?
Formula
Which of the following would be considered a formula?
2+5
Which of the following is an example of an Excel formula for taking the number 6 to the power of 2?
=6^2
What symbol is used for representing the mathematical operator "division" when using Excel?
/
What symbol is used for representing the mathematical operator "multiplication" when using Excel?
*
What symbol is used for representing the mathematical operator "subtraction" when using Excel?
-
In Excel, what is a collection of cells called?
Range
Which of the following formulas subtracts the value of 3 from 6 and multiplies the outcome by 2?
=(6-3)*2
Which of the following formulas averages the values of 6, 5, 7, 4, and 10?
AVERAGE (10, 4, 5, 6, 7)
What was the first ever Excel-like computer application called?
Visicalc
Most of the basic statistical procedures were first developed and used in agriculture and which of the following fields?
Astronomy
Every formula contains the name of the function and the function's what?
Argument
An argument in mathematical terms is which of the following?
A set of premises
Which of the following formulas will add each of the scores together and divide the sum by 3?
(x+y+z)/3
You can see the formula behind the screens in a worksheet by entering what?
Ctrl+'
Where will the results of the formula appear when you hit the Enter key?
In the selected cell
The mode measures central tendency in terms of which of these?
The most common score
Which of the following is the easiest way to describe data?
Average
Which of the following measures of central tendency is the midpoint for a set of scores?
Median
What is the most common type of average reported?
Mean
When using the AVERAGE function in Excel, which of these are you calculating?
Mean
Which of the following is the correct function for calculating the midpoint?
MEDIAN(A1:A10)
To identify the point in a distribution at which 50% of scores fall above and 50% fall below a given score, which measure of central tendency would you report?
Median
If you wanted to identify the most frequently occuring score in a distribution, which measure of central tendency would you report?
Mode
Which of the following is the correct function for calculating the score occurring most often in a distribution?
MODE (A1:A12)
The median is the score of the middle case when the number of cases in the data set is which of the following?
An odd number
Which of the following requires you to multiply a set of scores by the frequency of their occurrence, add the total of these products, and divide by the total number of scores?
Weighted mean
Which of the following is like the fulcrum on a seesaw?
Mean
What is the term associated with scores that are at the extreme ends of the distribution?
Outliers
What is the term for a distribution that is significantly distorted?
Skew
In the formula for computing the mean, what does the letter X represent?
Individual scores
In the formula for computing the mean, what does the Greek letter "Z" represent?
Summation
In the formula for computing the mean, what does the letter "n" represent?
Sample size
In a ranked list of 25 scores, the median is the score of
the 13th case
Which of the following is correct formula for calculating the mean?
ZX/n
Who was the inventor of the correlation?
Francis Galton
The average and which of the following can be used to describe the characteristics of a distribution and show how distributions differ from one another?
Variability
Variability is a measure of how much each score in a group of scores differs from the what?
Mean
The three measures of variability commonly used to reflect the spread or dispersion in a group of scores are the standard deviation, the variance, and what?
Range
When subtracting the largest number in a distribution from the smallest, what type of variability is being calculated?
Range
What is the term associated with scores that are at the extreme ends of the distribution?
Outliers
If a distribution is "significantly distorted" what is this called?
Skew
In the formula for computing the range, what does the letter "h" represent?
highest score
When calculating the standard deviation, what must be done in order to obtain an unbiased estimate of the population?
Subtract 1 from n
Which of the following sets of scores has the most variability?
7, 10, 11, 15, 19
What is the most general measure of variability?
Range
What is the formula for the exclusive range?
h-l
What is the formula for the inclusive range?
h-l+1
Which of the following is the correct function for calculating an unbiased estimate of the variance in the population?
VAR(A1:A12)
What will the sum of the deviations from the mean always equal?
0
What is obtained by squaring the standard deviation?
Variance
Which of the following is one way to represent variance?
s^2 (s to the power of 2)
What is the most frequently used measure of variability?
Standard deviation
If you intend to use a sample as an estimate of a population parameter, which standard deviation is the best to calculate?
Unbiased
which of the following are among the things to remember when creating figures?
Maintain the scale in the graph
What is the most basic method of illustrating data?
Frequency distribution
Which of the following is a method o tallying, and representing, how often a certain score occurs?
Frequency distribution
What is the term associated with a range of numbers that spans a set number of scores used when creating frequency distributions?
Class interval
What type of graph displays class intervals along an x-axis?
Histogram
In order to create a histogram in Excel, you must identify the "bins" you want. To what are the bins referring?
Class interval
What do you call a continuous line that represents the frequency of scores within a class interval?
Polygon
What is the term associated with the lack of symmetry in a distribution?
Skewness
In order to say that a distribution is positively skewed, which of the following must be true?
Right tail must be longer than the left
When the left tail of a distribution's curve is longer than the right, what is this called?
Negative skew
When the right tail of a distribution's curve is longer than the left, what is this called?
Positive skew
What is the term associated with how flat or peaked a distribution appears?
Kurtosis
Which of the following refers to a distributions's curve that is relatively peaked in comparison to a normal curve?
Leptokurtic
Which of the following refers to a distribution's curve that is relatively flat in comparison to a normal curve?
Platykurtic
Which of the following Excel functions will allow you to examine the symmetry of a set of scores?
SKEW(A1:A20)
If the mean of a set of scores is greater than the median, what can be said about the distribution?
Positively skewed
If the median of a set of scores is greater than the mean, what can be said about the distribution
Negatively skewed
Using the Excel Charts program, if you wanted to examine the proportion of students in this class who are male compared to female, which of the following might you use?
Column chart
If you were interested in tracking your GPA during the time you are in graduate school, which of the following might you use?
Line graph
Who is responsible for the invention of the Pearson product-moment correlation
Karl Pearson
When interested in examining how one variable changes in relation to another, which of the following descriptive statistics would you want to use?
Correlation
Which of the following is a measure of central tendency?
Mean
Which of the following refers to a correlation between two variables?
Bivariate
A correlation can range in value. Which of the following illustrates this range?
-1.0 to 1.0
If variables change in the same direction, what type of correlation is this called?
Positive correlation
If variables change in the opposite direction, what type of correlation is this called?
Negative correlation
The correlation between variable X and variable Y is represented by which of the following?
R>xy
Which of the following represent the Excel function to be used when computing correlation coefficients?
CORREL(A1:A10; B1:B10)
What would you use to represent a correlation visually
Scatterplot
When data points group together in a cluster from the lower left-hand side of the xy axis to the upper right-hand side, what is this?
Positive slope
Which of the following correlations would be interpreted as a very strong relationship?
.80
Which of the following correlations would be interpreted as a strong relationship?
.79
Which of the following correlations would be interpreted as a moderate relationship?
.45
Which of the following correlations would be interpreted as a weak relationship?
.26
If you wanted to compute the correlations between two interval-level variables, which type of correlation should you use?
Pearson
If you wanted to compute the correlation between two nominal-level variables, which type of correlation should you use?
Phi
If you wanted to compute the correlation between two ordinal-level variables, which type of correlation should you use?
Spearman rank
If the coefficient of determination between two variables is.81, what is the Pearson correlation coefficient?
.90
If the coefficient of determination between two variables is .81, what is the coefficient of alienation?
.19
Which of the following is concerned with monitoring estimates of present performance and predictions of future performance?
Criterion validity
What type of validity is concerned with the adequate representation of test items?
Content validity
what type of validity is concerned with the adequate representation of test items?
Content validity
If you want to know that a test measures some underlying psychological construct, what type of validity evidence would you want to collect?
Construct validity
If you correlate scores from your test with some other valid measure that assesses the same set of abilities, what type of validity evidence are you collecting?
Criterion validity
If I can say that my weekly statistics quiz fairly assesses the material covered, what source of validity evidence should I have collected?
Content validity
What is the key to establishing criterion validity?
Quality of the criterion
High school class rank is highly correlated with college GPA. This is an example of what type of validity?
Predictive validity
A score that you would actually record is an example of which of the following?
Observed score
A measure of how stable a test is over time is an example of which of the following?
Test-retest reliability
Which coefficient reflects the occurrence of a perfect reliability?
+1.00
Two trained professionals observe the behavior of children in a classroom. They each rate observed behaviors...
Interrater reliability
If the measures associates with a test are said to be consistent, you might conclude that the measure is which of the following?
Reliable
When we calculate reliability, we know the observes score. What are the two unknown components of the reliability equation?
True and error scores
how does interrater reliability measure consistency?
From rater to rater
Which of the following is the Greek letter associated with Cronbach's alpha, sometimes known as coefficient alpha?
a
Test-retest reliability is an example of which of the following?
Measure of stability
parallel forms reliability is an example of which of the following?
Measure of equivalence
Interrater reliability is an example of which of the following?
Measure of equivalence
Interrater reliability is an example of which of the following?
Measure of agreement
What would the interrater reliability be for a 50-item measure in which the number of agreements between Rater 1 and Rater 2 was 45?
.90
What ar the four levels of measurement?
Nominal, ordinal, interval, ratio